openmv/scripts/examples/Arduino/37-Audio/audio_fft.py
2020-11-20 19:43:58 +02:00

45 lines
1.4 KiB
Python

import image, audio, time, array, math, ulab as np
from ulab import extras, numerical
SIZE = 512//4
pcm_buf = None
fb = image.Image(SIZE+50, SIZE, image.RGB565, copy_to_fb=True)
audio.init(channels=2, frequency=16000, gain=24, highpass=0.9883)
def audio_callback(buf):
global pcm_buf
if (pcm_buf == None):
pcm_buf = np.array(array.array('h', buf))
# Start audio streaming
audio.start_streaming(audio_callback)
def draw_fft(img, fft_buf):
fft_buf = (fft_buf / max(fft_buf)) * SIZE
fft_buf = np.vector.log10(fft_buf + 1) * 20
color = (0xFF, 0x0F, 0x00)
for i in range(0, SIZE):
img.draw_line(i, SIZE, i, SIZE-int(fft_buf[i]), color, 1)
def draw_audio_bar(img, level, offset):
blk_size = SIZE//10
color = (0xFF, 0x00, 0xF0)
blk_space = (blk_size//4)
for i in range(0, int(round(level/10))):
fb.draw_rectangle(SIZE+offset, SIZE - ((i+1)*blk_size) + blk_space, 20, blk_size - blk_space, color, 1, True)
while (True):
if (pcm_buf != None):
fb.clear()
fft_buf = extras.spectrogram(pcm_buf[0::2])
l_lvl = int((numerical.mean(abs(pcm_buf[1::2])) / 32768)*100)
r_lvl = int((numerical.mean(abs(pcm_buf[0::2])) / 32768)*100)
pcm_buf = None
draw_fft(fb, fft_buf)
draw_audio_bar(fb, l_lvl, 0)
draw_audio_bar(fb, r_lvl, 25)
fb.flush()
# Stop streaming
audio.stop_streaming()